A - Do you agree that according to the global temperature record used by the IPCC, the rates of global warming from 1860-1880, 1910-1940 and 1975-1998 were identical?

An initial point to make is that in the responses to these questions I've assumed that when you talk about the global temperature record, you mean the record that combines the estimates from land regions with those from the marine regions of the world. CRU produces the land component, with the Met Office Hadley Centre producing the marine component.

Temperature data for the period 1860-1880 are more uncertain, because of sparser coverage, than for later periods in the 20th Century. The 1860-1880 period is also only 21 years in length. As for the two periods 1910-40 and 1975-1998 the warming rates are not statistically significantly different (see numbers below).

I have also included the trend over the period 1975 to 2009, which has a very similar trend to the period 1975-1998.

So, in answer to the question, the warming rates for all 4 periods are similar and not statistically significantly different from each other.

Here are the trends and significances for each period:

This is pretty significant because Jones is admitting that—over the timescale for which we have actual measurements (rather than proxies)—the current warming trend is not unprecedented—an aspect that the whole alarmist argument depends on.

I think some of these conclusions are a bit of a reach from the Q&A. I don’t get the sense that Jones is abandoning the basic hypothesis that climate sensitivity to manmade CO2 is high (e.g. 3+ degrees per doubling, rather than <=1 degrees as many skeptics would hypothesize). In particular, I think the writing has been on the wall for a while that alarmists were bailing on the hockey stick / MWP-related arguments as indicative of high sensitivities.

The new news for me was the admission that the warming rate from 1979-present is in no way unprecedented. This is important as the lead argument (beyond black box “the models say so” justifications) for blaming anthropogenic factors for recent warming is that the rate of warming was somehow unprecedented. However, Jones admits (as all rational skeptics have said for some time) that the warming rate from 1979 to today is really no different than we have measured in other periods decidedly unaffected by CO2.

However, there was one of Phil Jones's answers that left me absolutely gob-smacked, and it is this one:

H - If you agree that there were similar periods of warming since 1850 to the current period, and that the MWP is under debate, what factors convince you that recent warming has been largely man-made?

The fact that we can't explain the warming from the 1950s by solar and volcanic forcing - see my answer to your question D [where he referenced Chapter 9 of the IPCC AR4].

You what? So, since you are unable to account for the warming in terms of volcanos or solar warming, then it must be human induced? What the hell?

What about this mysterious decadal Pacific oscillation that is now, apparently, "masking the warming"? What about cloud formation, or albedo or... or... so many other bloody things, many of which we may not be aware of? The climate is a pretty Chaotic system and we have, really, very little idea of all of the factors involved. Yes, it may be man-made forcings but, ultimately, it could be something else entirely. Or a mixture of both natural and human, of course.

Still, we are constantly told that the debate is over, aren't we, Phil?

It would be supposition on my behalf to know whether all scientists who say the debate is over are saying that for the same reason. I don't believe the vast majority of climate scientists think this. This is not my view. There is still much that needs to be undertaken to reduce uncertainties, not just for the future, but for the instrumental (and especially the palaeoclimatic) past as well.

Ah. So the debate isn't over? And the "vast majority of climate scientists think this"? Right.

Well, thank you for indulging us poor climate "deniers"—or, in the words of the Prime Minister of Great Britain, we "anti-science, flat-earth climate sceptics"—and admitting that there is a debate to be had: that's tremendously kind of you, Phil.

This is very far from being a smoking gun interview and Jones is obviously still of the opinion that man is the cause of the world's warming but, nonetheless, this climate scientist obviously feels that there is still a debate to be had.

So, after many long years of vilifying sceptics and shutting down any comment, perhaps we can have a grown-up debate.

Computer models are not up to the job of predicting such a chaotic system as the worlds weather.Far too many variables.Even for massive proccesing power.It was suggested that the flap of a butterflies wings in South America could theoretically set up a chain of events leading to tornados in the American mid west.The games up you've been cuaght on the fiddle.Time to pay the piper.

I see that the 1930/40 figure was lower than the rest. Born in 1933 in an industrial area I can say that the pollution levels were on todays standards horrendous. Then add in the wartime period 39/45, bombs, shell and gun explosions to say nothing of the fires so caused, that should have raised the temperature a bit. Most people talking about pollution have never seen it in the real world, before the "clean air act", in the, what 50s I think.

a) Derek - you need to distinguish between pollutants and CO2 emissions. The Clean Air Act and its equivalents elsewhere took huge strides in reducing pollution from smokestacks. However, they did bugger-all to reduce CO2 emissions, which they were not concerned with. CO2 emissions have risen throughout the industrial age. Only recessions have had any limited effect on reducing their rate of growth.

b) Sunni is is a complete cretin isn't he? He avers that "IPCC head Dr Rajendra Pachauri [is] rightly refusing to apologise for a mistake that wasn't made under his watch". However, he believes the monarchy should apologise for slavery, because the institution was around when slavery abounded. Consistency not his strong point.

Given what comes out of them tends to be things like deserts drying, rainy areas getting heavier rains, snowy areas getting more snow, variable regions becoming more variable I guess they do nothing more complicated than take recent weather trends and extrapolate them for 100 years into the future, being totally reliant on those recent weather trends being caused by increased CO2.

I can claim to having an interest in this subject , namely that i never thought for a moment that the IPCC would make up stories or for that matter the CRP would put out mis leading information.

I have long held the position that digging up carbon sequestered from millions of years of eco system , and then converting it into oxides and heat , would have an effect.

We know that certain gaseous oxides are harmfull to life , but the question about warming is spurious , as all along pollution/toxin was the problem .

The oxide sequestering systems of the planet , may still be in trouble from pollution , the nordic forest acidification was proven , the oxides mixed with the water vapour to produce weak acids , the acid rain in turn changed nutirent levels and damaged tree cell/leaf structures .

The oceans abosrb a lot of oxides and many questions still remain about what systems are absorbinng what , in other words where are all the by products going ??

There is also the more difficult idea of how much nature and perhaps , how much of the high solar tropical rainforests (equator to tropics) which are the most energetic sequestering areas .

It is clear that there is somthing true in that nature can only support a certain population , forests/wilderness have a quiet role in maintaing the conditions for respiratory life.

That said I cannot convey how bitter it is to find , false preachers with such weak authority and empty claims/lies , for what looks like a fit to certain ecnomic structures , whilst not adressing the real problems of increasing population and increasing man made pollution and loss of important ecosystems .